Role of Immunotherapy in Triple-Negative Breast Cancer

Antimicrobial peptide WK-13-3D promotes apoptosis, autophagy, and ubiquitination in triple-negative breast cancer via binding immunoglobulin protein (BiP)

PURPOSE

To elucidate the inhibitory mechanism of antimicrobial peptide WK-13-3D on triple-negative breast cancer (TNBC) by targeting the binding immunoglobulin protein (BiP), a key endoplasmic reticulum (ER) chaperone regulating unfolded protein response and tumor survival.

METHODS

TNBC cell lines (MDA-MB-231 and MDA-MB-468) were treated with WK-13-3D to assess proliferation, migration, invasion, and apoptosis. Pull-down assays identified interacting proteins, and Western blotting (WB) analyzed alterations in BiP, PERK, eIF2α, p-eIF2α, Caspase3, Cleaved-Caspase3, Bax, LC3, P62, AKT, p-AKT, mTOR, and p-mTOR. Transmission electron microscopy examined intracellular structures, while qPCR measured BiP mRNA levels. The effects of WK-13-3D on BiP ubiquitination were explored via co-immunoprecipitation (Co-IP). Animal tumor models were used to confirm the inhibitory effects, with BiP and Ki67 (a nuclear proliferation marker indicating actively dividing tumor cells) expression analyzed by immunohistochemistry (IHC).

RESULTS

WK-13-3D inhibited TNBC cell proliferation, migration, and invasion, while promoting apoptosis. Pull-down experiments identified 268 interacting proteins, with BiP being the most frequent. Databases (TIMER and TCGA) showed high BiP expression in breast cancer, associated with poor prognosis. WB assays revealed that WK-13-3D activated ER stress-induced apoptosis and autophagy via BiP. Co-IP demonstrated that WK-13-3D mediated BiP ubiquitination at sites 352 and 547 through K6 and K29 chains. IHC analysis further confirmed decreased Ki67 levels in WK-13-3D-treated tumors, reflecting suppressed proliferative activity. Animal experiments confirmed tumor growth inhibition.

CONCLUSION

WK-13-3D promotes apoptosis, autophagy and Ubiquitination in TNBC by modulating BiP.

A self-accelerating 'copper bomb' strategy activated innate and adaptive immune response against triple-negative breast cancer

Triple-negative breast cancer (TNBC) presents therapeutic challenges due to its aggressive, drug-resistance, and low immunological reactivity. Cuproptosis, an emerging therapeutic modality, is a promising strategic intervention for treating TNBC. Nonetheless, the effectiveness of cuproptosis is compromised by tumor adaptations, including the Warburg effect, increased intracellular glutathione (GSH), and copper efflux, thus breaking the barrier of cuproptosis is the basis for developing cuproptosis-based clinical therapies. Herein, a self-accelerating strategy utilizing a pH-responsive copper framework encapsulating glucose oxidase (GOx), modified with polyethylene glycol (PEG) and tumor-penetrating peptide (tLyp1) has been developed. Upon reaching the acidic tumor microenvironment, the released GOx increases intracellular acidity and hydrogen peroxide (H2O2). The elevated intracellular GSH and H2O2 serve as "fuel" to amplify the copper-based catalytic within tumor cells. Concurrently, the reduction of copper efflux proteins (ATP7B) and the depletion of GSH lead to copper overload in tumor cells, leading to cuproptosis via copper overload, mitochondrial disruption, and Fe-S protein instability. This constellation of interrelated events constitutes a potent "Copper Bomb," which concurrently triggers the immune system and effectively kills the tumor. It robustly engages innate and adaptive immunity via the release of mitochondrial DNA, facilitating the cGAS-STING pathway and precipitating immunogenic cell death. This process reverses the immunosuppressive tumor microenvironment, eliminates tumor cells, and suppresses metastasis, thus offering a novel therapeutic modality for the comprehensive treatment of triple-negative breast cancer (TNBC).

Copper-based hollow mesoporous nanogenerator with reactive oxygen species and reactive nitrogen species storm generation for self-augmented immunogenic cell death-mediated triple-negative breast cancer immunotherapy

Although nanotheranostics have great potential in tumor immunotherapy, their effectiveness is often hindered by low immunogenic cell death (ICD) and inactivated immune responses in the tumor immunosuppressive microenvironment (TIME). Such vulnerability may lead to metastasis or recurrence, especially in triple-negative breast cancer (TNBC). Addressing this challenge, the study presents a multimodal immunotherapeutic approach using a self-enhanced ICD copper (Cu)-based hollow nanogenerator. This nanogenerator is activated by a near-infrared (NIR) laser to produce reactive oxygen species (ROS) and reactive nitrogen species (RNS) storms. Specifically, the nitric oxide (NO) donor l-Arginine (l-Arg) is loaded into hollow mesoporous Cu sulfide nanoparticles (HCuSNPs) with inherent NIR absorption and coated with tumor-targeting peptides (RGD), forming l-Arg@HCuSNPs-PEG-RGD (AHPR). In vitro and in vivo experiments demonstrate that AHPR can induce tumor thermal ablation, cuproptosis, and the generation of peroxynitrite anions (ONOO-) under NIR laser irradiation, resulting in multiple antitumor effects. Additionally, the nanogenerator enhances ICD through mechanisms such as mild-photothermal therapy (mPTT), cuproptosis, and ONOO- production, promoting immune cell infiltration and activation, and converting 'cold' tumors into 'hot' ones. By combining AHPR with the immune checkpoint inhibitor anti-programmed cell death protein ligand-1 antibody (αPD-L1), the study significantly improves the immunotherapy response rate in TNBC, offering a promising strategy to enhance TNBC immunotherapy efficacy.

A potential therapeutic molecule target: lncRNA AK023507 inhibits the metastasis of breast cancer by regulating the WNT/DOCK4/β-catenin axis

PURPOSE

Breast cancer (BC) has become the most common malignant tumor in women worldwide. This study was carried out to find and validate a novel molecular therapeutic target for BC.

METHODS

Long non-coding RNA (lncRNA) AK023507 was selected as the study objects through microarray analysis. The function of lncRNA AK023507 was verified by various cell function experiments in vitro, subcutaneous tumorigenesis experiments, and lung metastasis model experiments in vivo. The RNA pull-down experiment and Western blot experiment were used to confirm the mechanism regulation pathway and the recovery experiment was used to verify it. TCGA datasets were used for clinical and immune function prediction analysis.

RESULTS

In vitro cell function tests and in vivo experiments suggested that overexpression of lncRNA AK023507 inhibited the proliferation and metastasis of BC cells. The RNA pull-down experiment and Western blot analysis validated that lncRNA AK023507 interacted with the dedicator of cytokinesis 4 (DOCK4) protein. Analysis of public databases predicted that DOCK4 is a potential prognostic risk factor associated with epithelial-mesenchymal transition (EMT) and central memory T cell (TCM) cellular immune infiltration.

CONCLUSIONS

LncRNA AK023507 inhibits the proliferation and metastasis of BC by regulating the DOCK4/β-catenin axis. This discovery will provide new potential therapeutic targets for BC.

High Expression of Calreticulin Affected the Tumor Microenvironment and Correlated With Worse Prognosis in Patients With Triple-Negative Breast Cancer

Calreticulin (CALR) preserves reticular homeostasis by maintaining correct protein folding within the endoplasmic reticulum. Immunogenic cell death (ICD) is a regulated form of cell death and could activate adaptive immune response. As one of the damage-associated molecular patterns during ICD process, surface-exposed CALR resulted in the activation of adaptive immune response. Here, we evaluated the expression patterns of CALR in a cohort of 231 untreated triple-negative breast cancer (TNBC) and determined correlations between CALR expression and clinicopathologic parameters, programmed cell death ligand 1 (PD-L1) expression in immune cells (ICs), and survival. In addition, we analyzed a TNBC data set from The Cancer Genome Atlas to explore the relationship between mRNA expression of CALR and clinicopathologic features, IC infiltration, and survival. Tissue microarray results showed that high CLAR was strongly correlated with advanced stage ( P = 0.022), shorter disease-free survival ( P = 0.008) and overall survival ( P = 0.002), and independently predicted prognosis in TNBC. Spearman analyses demonstrated that CALR negatively correlated with PD-L1 in ICs ( r = -0.198, P = 0.003). Patients with low CALR and high PD-L1 in ICs had the best disease-free survival ( P = 0.013) and overall survival ( P = 0.004) compared with other patients, especially the patients with high CALR and low PD-L1 in ICs. In the "The Cancer Genome Atlas" cohort, CALR mRNA expression in tumors was significantly higher than that in normal tissues ( P < 0.001). CALR expression was strongly and positively related to other ICD-related genes. These findings demonstrated that the expression of CALR could independently predict the prognosis in patients with TNBC, and it may play a potential synergistic role in treatments involving immunotherapy.

Targeting of the IL-33/Wnt axis restricts breast cancer stemness and metastasis

Interleukin-33 (IL-33) plays multifaceted roles in tumor progression, but its autocrine regulation of breast cancer stemness and metastasis via the Wnt pathway remains unclear. Here, we investigated the IL-33/ST2 axis in breast cancer using CRISPR/Cas9, single-cell RNA sequencing, and murine models (orthotopic 4T1 and spontaneous MMTV-PyMT). Elevated IL-33 levels correlated with aggressive subtypes and poor prognosis. IL-33 overexpression enhanced proliferation, migration, and cancer stem cell (CSC) marker expression (CD44, ALDH1) in 4T1 and MDA-MB-231 cells, whereas ST2 knockdown via CRISPR or adeno-associated virus (AAV) attenuated tumor growth and metastasis in vivo, reducing CSC frequency. Mechanistically, IL-33 activated Wnt/β-catenin signaling to promote stemness, which was reversed by the Wnt inhibitor XAV-939. Single-cell analysis revealed that IL-33 overexpression skewed the immune microenvironment toward immunosuppression, while ST2 knockdown restored antitumor immunity. Our findings establish an IL-33-Wnt axis as a critical driver of breast cancer aggressiveness and propose AAV-mediated ST2 silencing as a novel therapeutic strategy. Targeting this axis may offer dual benefits by suppressing stemness and enhancing immune surveillance, warranting clinical exploration for advanced breast cancer.

Inhibition of UCH-L1 enhances immunotherapy efficacy in triple-negative breast cancer by stabilizing PD-L1

Recent research indicates that programmed death 1 (PD-1) and programmed death-ligand 1 (PD-L1) inhibitors show promise in treating triple-negative breast cancer (TNBC), but their efficacy is lower than anticipated, especially when used alone. Therefore, enhancing the anti-tumor immune response strategy for TNBC is crucial. Ubiquitin carboxy-terminal hydrolase L1 (UCH-L1), involved in tumor cell regulation and a potential therapeutic target, has an undefined role in TNBC immunotherapy. In this study, we explored the inverse correlation between UCH-L1 and PD-L1 in TNBC patient tissues. Through in vitro experiments, we found that UCH-L1 negatively regulates PD-L1 by stabilizing the E3 ubiquitin ligase ariadne-1 homolog (ARIH1), which promotes PD-L1 ubiquitination and degradation. Further analysis in Balb/c mice xenograft tumors showed that UCH-L1 correlates with GZMB+/CD8+ T cell infiltration in TNBC, suggesting potential synergistic effects when combining UCH-L1 inhibitors with PD-L1 antibodies. Overall, in TNBC, UCH-L1 stabilizes ARIH1, leading to low PD-L1 expression, which may explain the limited effectiveness of immunotherapy in TNBC patients. Our mouse experiments showed improved therapeutic effects when combining UCH-L1 inhibitors with PD-L1 antibodies. These findings offer a new avenue for immunotherapy in TNBC patients.

Machine learning and single-cell analysis uncover distinctive characteristics of CD300LG within the TNBC immune microenvironment: experimental validation

Investigating the essential function of CD300LG within the tumor microenvironment in triple-negative breast cancer (TNBC). Transcriptomic and single-cell data from TNBC were systematically collected and integrated. Four machine learning algorithms were employed to identify distinct target genes in TNBC patients. Specifically, CIBERSORT and ssGSEA algorithms were utilized to elucidate immune infiltration patterns, whereas TIDE and TCGA algorithms predicted immune-related outcomes. Moreover, single-cell sequencing data were analyzed to investigate the function of CD300LG-positive cells within the tumor microenvironment. Finally, immunofluorescence staining confirmed the significance of CD300LG in tumor phenotyping. After machine learning screening and independent dataset validation, CD300LG was identified as a unique prognostic biomarker for triple-negative breast cancer. Enrichment analysis revealed that CD300LG expression is strongly linked to immune infiltration and inflammation-related pathways, especially those associated with the cell cycle. The presence of CD8+ T cells and M1-type macrophages was elevated in the CD300LG higher group, whereas the abundance of M2-type macrophage infiltration showed a significant decrease. Immunotherapy prediction models indicated that individuals with low CD300LG expression exhibited better responses to PD-1 therapy. Additionally, single-cell RNA sequencing and immunofluorescence analyses uncovered a robust association between CD300LG and genes involved in tumor invasion. CD300LG plays a pivotal role in the tumor microenvironment of TNBC and represents a promising therapeutic target.

The integrated single-cell analysis interpret the lactate metabolism-driven immune suppression in triple-negative breast cancer

BACKGROUND

Individuals with triple-negative breast cancer (TNBC) exhibit elevated lactate levels, which offers a valuable lead for investigating the molecular mechanisms underlying the tumor microenvironment (TME) and identifying more efficacious treatments.

METHODS

TNBC samples were classified based on lactate-associated genes. A single-cell transcriptomic approach was employed to examine functional differences across cells with varying lactate metabolism. Immunohistochemistry was used to explore the relationship between lactate metabolism and the CXCL12/CXCR4 signaling axis. In addition, utilizing machine learning techniques, we constructed a prognostic model based on lactic acid phenotype genes.

RESULTS

Lactate-associated gene-based stratification revealed increased immune cell infiltration and immune checkpoint expression in Lactate Cluster 1. Elevated lactate metabolism scores were observed in both cancer-associated fibroblasts (CAFs) and malignant cells. CAFs with high lactate metabolism exhibited immune suppression through the CXCL12/CXCR4 axis. Immunohistochemistry confirmed elevated LDHA, LDHB, CXCL12, and CXCR4 levels in the high lactate group.

CONCLUSION

This study elucidates the complex interplay between lactate and immune cells in TNBC and highlights the CXCL12/CXCR4 axis as a key pathway through which lactate mediates immune suppression, offering new insights into metabolic regulation within the TME. Furthermore, we developed a prognostic model based on lactate metabolism phenotype genes to predict the prognosis of TNBC patients and guide immunotherapy.

A coagulation-related long non-coding RNA signature to predict prognosis and immune features of breast cancer

Breast cancer (BC) remains one of the most common malignancies among women worldwide, with persistently poor prognosis despite advancements in diagnostics and therapies. Long non-coding RNAs (lncRNAs) and coagulation-related genes (CRGs) are increasingly recognized for their roles in prognosis and immune modulation. Using transcriptomic data from 1,045 BC patients in TCGA, we identified CRG-associated lncRNAs via coexpression analysis (Pearson |R|> 0.4, p < 0.001) and constructed a prognostic model through univariate Cox analysis, LASSO regression with tenfold cross-validation (λ = 0.05), and multivariate Cox analysis. The model stratified patients into high- and low-risk groups with distinct overall survival (HR = 3.21, p < 0.001) and demonstrated robust predictive accuracy (AUC = 0.795 at 1 year). Functional enrichment revealed immune-related pathways (e.g., cytokine signaling, PD-L1 regulation), and high-risk patients exhibited elevated tumor mutational burden (TMB) and PD-L1 expression, suggesting enhanced immunotherapy responsiveness. Drug sensitivity analysis identified 5 targeted agents (e.g., BIBW2992) with differential efficacy between risk groups. This CRG-lncRNA signature provides a novel tool for prognosis prediction and personalized immunotherapy in BC, illuminating crosstalk between coagulation and immune pathways.

Harnessing Tumor-Infiltrating Lymphocytes in Triple-Negative Breast Cancer: Opportunities and Barriers to Clinical Integration

Triple-negative breast cancer (TNBC) continues to present a therapeutic challenge due to the fact that by definition, these cancer cells lack the expression of targetable receptors. Current treatment options include cytotoxic chemotherapy, antibody-drug conjugates (ADC), and the PD-1 checkpoint inhibitor, pembrolizumab. Due to high rates of recurrence, current guidelines for early-stage TNBC recommend either multi-agent chemotherapy or chemo-immunotherapy in all patients other than those with node-negative tumors < 0.5 cm. This approach can lead to significant long-term effects for TNBC survivors, driving a growing interest in de-escalating therapy where appropriate. Tumor infiltrating lymphocytes (TILs) represent a promising prognostic and predictive biomarker for TNBC. These diverse immune cells are present in the tumor microenvironment and within the tumor itself, and multiple retrospective studies have demonstrated that a higher number of TILs in early-stage TNBC portends a favorable prognosis. Research has also explored the potential of TIL scores to predict the response to immunotherapy. However, several barriers to the widespread use of TILs in clinical practice remain, including logistical and technical challenges with the scoring of TILs and lack of prospective trials to validate the trends seen in retrospective studies. This review will present the current understanding of the role of TILs in TNBC and discuss the future directions of TIL research.

Impact of postmastectomy radiotherapy on locoregional recurrence and survival in patients with ypN0 breast cancer after neoadjuvant chemotherapy: A comprehensive meta-analysis and systematic review

BACKGROUND

The necessity of postmastectomy radiotherapy (PMRT) following neoadjuvant chemotherapy (NAC) in patients with ypN0 breast cancer remains a controversial clinical issue. To elucidate this issue, the present study performed a systematic review and meta-analysis, focusing on studies of clinically lymph node-negative patients exhibiting a favorable pathologic response to NAC.

MATERIALS AND METHODS

After a comprehensive literature search of PubMed and major oncology congress abstracts, 16 studies that met the inclusion criteria were included. A fixed or random effects model was used to assess the impact of PMRT on the local recurrence rate (LRR) and survival outcomes, where appropriate.

RESULTS

The pooled data from ten studies indicated that PMRT significantly reduced the LRR in patients with ypN0 breast cancer (risk ratio [RR], 0.52; 95% confidence interval [CI], 0.41-0.67, P < 0.00001). Moreover, a marginal increase in the overall survival (OS) rates was observed in nine studies (RR, 1.01; 95% CI, 1.00-1.02, P = 0.006), whereas no significant effect on disease-free survival (DFS) was found in six studies (RR, 1.01; 95% CI, 0.95-1.08, P = 0.72).

CONCLUSIONS

Our findings suggest that PMRT is associated with reduced LRR and slightly improved OS in patients with ypN0 breast cancer. However, prospective studies are needed to provide more evidence and inform clinical decision-making.

Angiogenesis and immune microenvironment in triple-negative breast cancer: Targeted therapy

Triple-negative breast cancer (TNBC) is a highly aggressive breast cancer subtype that typically lacks effective targeted therapies, leading to limited treatment options. Chemotherapy remains the primary treatment modality; however, in recent years, new immunotherapy approaches, such as immune checkpoint inhibitors, have shown positive results in some patients. Although the development of TNBC is closely associated with BRCA gene mutations, the tumor immune microenvironment (TIME) plays a crucial role in tumor progression and immune escape. Tumor angiogenesis, the accumulation of immunosuppressive cells, and alterations in immune molecules collectively shape an environment unfavorable for anti-tumor immune responses. Tumor-associated macrophages (TAMs) and myeloid-derived suppressor cells (MDSCs) promote immune escape by secreting immunosuppressive factors. Therefore, combination strategies of anti-angiogenic and immune checkpoint inhibitory therapies have shown synergistic effects in clinical trials, while new targeted therapies such as TGF-β inhibitors and IL-1β inhibitors offer new options for TNBC treatment. With the development of personalized medicine, combining immunotherapy and targeted therapies brings new hope for TNBC patients.

Comprehensive analysis of breast cancer oxidative stress related gene signature: a combination of bulk and single-cell RNA sequencing analysis

Oxidative stress influences the tumor microenvironment, driving breast cancer progression and drug resistance. This study aimed to develop a prognostic gene signature based on oxidative stress-related genes (OSRGs) to assess patient outcomes and immune status. UCSC Xena ( http://xena.ucsc.edu/ ) and GEO ( https://www.ncbi.nlm.nih.gov/geo/ ) databases were used to obtain RNA-seq data and corresponding clinical information. The classification of OSRG subtypes was performed using consensus cluster. The oxidative stress related scoring (OSRS) model was established combining Lasso regression and multivariable Cox regression. The analysis of tumor mutation burden (TMB) and somatic mutation were carried out using the R package 'maftools'. Python package 'pySCENIC' was used to construct and analyze the transcription factor network. Additionally, immune infiltration was analyzed using R packages 'CIBERSORT' and 'ESTIMATE'. Three OSRG subgroups were identified and the Differentially Expressed Genes (DEGs) among them were enriched in humoral immunity, cytokine communication and drug metabolism pathways. OSRS model was established based on the DEGs and revealed association with patients' overall survival, somatic mutations, immune statuses, and drug resistance. Finally, transcription factor TFAP2B was identified as a key regulatory factor in high OSRS cells, and associated with a negative prognostic outcome in Basal-like breast cancer patients.

Tumor vascular normalization by B7-H3 blockade augments T lymphocyte-mediated antitumor immunity

Triple-negative breast cancer (TNBC), defined by the absence of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2), presents unique clinical challenges and generally predicts a less favorable prognosis. Despite recent advancements in TNBC treatment, a subset of patients remains resistant to immunotherapy. B7-H3, a member of the B7 family of immune checkpoints, is correlated with poor outcomes in various cancers and is distinctively expressed in tumor vasculature, marking it as a potential biomarker for tumor-associated endothelial cells. We found high expression of B7-H3 in the endothelial cells of the postoperative tissue of TNBC patients. Elevated gene expression of CD276 (encoding B7-H3) and PECAM1 (encoding CD31) in TNBC is associated with poor prognosis. Anti-B7-H3 blockade reduces tumor burden and promotes lymphocyte infiltration in a TNBC mouse model. Additionally, anti-B7-H3 blockade promotes tumor vessel normalization and enhances programmed cell death ligand 1 (PD-L1) expression. Synergistic effects were observed when B7-H3 blockade was combined with programmed cell death protein 1 (PD-1) inhibition in the TNBC mouse model. Furthermore, anti-B7-H3 inhibits human umbilical vein endothelial cell (HUVEC) proliferation by suppression of the nuclear factor kappa-B (NF-κB) signaling pathway. Downregulation of B7-H3 expression in HUVECs promotes lymphocyte trans-endothelial migration. These findings suggest that B7-H3 represents a promising therapeutic target for TNBC, and the combination of anti-B7-H3 and anti-PD-1 therapies may have synergetic effects in treating TNBC.

CXCR4/CXCL12 blockade therapy; a new horizon in TNBC therapy

The only subtype of breast cancer (BC) without specific therapy is triple-negative breast cancer (TNBC), which represents 15-20% of incidence cases of BC. TNBC encompasses transformed and nonmalignant cells, including cancer-associated fibroblasts (CAF), endothelial vasculature, and tumor-infiltrating cells. These nonmalignant cells, soluble factors (e.g., cytokines), and the extracellular matrix (ECM) form the tumor microenvironment (TME). The TME is made up of these nonmalignant cells, ECM, and soluble components, including cytokines. Direct cell-to-cell contact and soluble substances like cytokines (e.g., chemokines) may facilitate interaction between cancer cells and the surrounding TME. Through growth-promoting cytokines, TME not only enables the development of cancer but also confers therapy resistance. New treatment targets will probably be suggested by comprehending the processes behind tumor development and progression as well as the functions of chemokines in TNBC. In this light, several investigations have shown the pivotal function of the C-X-C motif chemokine ligand 12 (CXCL12 or SDF-1) axis and chemokine receptor type 4 (CXCR4) in the pathophysiology of TNBC. This review provides an overview of the CXCR4/CXCL12 axis' function in TNBC development, metastasis, angiogenesis, and treatment resistance. A synopsis of current literature on targeting the CXCR4/CXCL12 axis for treating and managing TNBC has also been provided.

Targeting PRDX2 to inhibit tumor growth and metastasis in triple-negative breast cancer: the role of FN1 and the PI3K/AKT/SP1 pathway

BACKGROUND

Triple-negative breast cancer (TNBC) is characterized by high invasiveness, high potential for metastasis, easy recurrence, and poor prognosis. There is an urgent need to develop new clinical treatments.

METHODS

This study utilized TNBC tissue microarrays to detect Peroxiredoxin 2 (PRDX2) expression levels and analyzed the correlation between PRDX2 and tumor invasion as well as invasion-related gene expression through the TCGA database. A stable PRDX2-knockdown triple-negative breast cancer cell line was established using lentiviral technology. The effects of PRDX2 on triple-negative breast cancer cell migration, invasion, and epithelial-mesenchymal transition (EMT) were investigated via wound healing assays, Transwell assays, qPCR, and Western blotting. RNA sequencing (RNA-seq), Western blotting, and dual luciferase reporter assays were performed to confirm that PRDX2 regulates FN1 expression through SP1. Furthermore, subcutaneous tumor xenograft models in nude mice were constructed to assess the effects of PRDX2 knockdown and the PRDX2 inhibitor Conoidin A on tumor growth in vivo.

RESULTS

Tissue microarray detection and correlative analysis revealed that PRDX2 is significantly upregulated in triple-negative breast cancer (TNBC) tumor tissues and positively correlated with genes associated with cell migration and invasion. Functional experiments demonstrated that in vitro knockdown of PRDX2 suppresses migration, invasion, and epithelial-mesenchymal transition (EMT) in TNBC cells. Furthermore, in vivo knockdown of PRDX2 or treatment with the PRDX2 inhibitor Conoidin A effectively reduced tumor burden. Mechanistic investigations utilizing RNA sequencing (RNA-seq) identified FN1 as a critical gene promoting TNBC cell migration and invasion. PRDX2 facilitates TNBC progression by activating the PI3K/AKT signaling pathway, which enhances SP1 binding to the FN1 gene promoter. This regulatory cascade ultimately drives tumor advancement in TNBC.

CONCLUSIONS

This study elucidates the role of the PRDX2/SP1/FN1 axis in TNBC migration and invasion, and highlights PRDX2 as a promising therapeutic target for triple-negative breast cancer.

Using Cancer-Associated Fibroblasts as a Shear-Wave Elastography Imaging Biomarker to Predict Anti-PD-1 Efficacy of Triple-Negative Breast Cancer

In the clinical setting, the efficacy of single-agent immune checkpoint inhibitors (ICIs) in triple-negative breast cancer (TNBC) remains suboptimal. Therefore, there is a pressing need to develop predictive biomarkers to identify non-responders. Considering that cancer-associated fibroblasts (CAFs) represent an integral component of the tumor microenvironment that affects the stiffness of solid tumors on shear-wave elastography (SWE) imaging, wound healing CAFs (WH CAFs) were identified in highly heterogeneous TNBC. This subtype highly expressed vitronectin (VTN) and constituted the majority of CAFs. Moreover, WH CAFs were negatively correlated with CD8+ T cell infiltration levels and influenced tumor proliferation in the Eo771 mouse model. Furthermore, multi-omics analysis validated its role in immunosuppression. In order to non-invasively classify patients as responders or non-responders to ICI monotherapy, a deep learning model was constructed to classify the level of WH CAFs based on SWE imaging. As anticipated, this model effectively distinguished the level of WH CAFs in tumors. Based on the classification of the level of WH CAFs, while tumors with a high level of WH CAFs were found to exhibit a poor response to anti programmed cell death protein 1 (PD-1) monotherapy, they were responsive to the combination of anti-PD-1 and erdafitinib, a selective fibroblast growth factor receptor (FGFR) inhibitor. Overall, these findings establish a reference for a novel non-invasive method for predicting ICI efficacy to guide the selection of TNBC patients for precision treatment in clinical settings.

Ferroptosis: a novel perspective on tumor immunotherapy

Ferroptosis is a novel form of programmed cell death characterized by iron-dependent accumulation of reactive oxygen species (ROS) and lipid peroxidation. The execution of ferroptosis is intricately linked to both iron and lipid metabolism. Intriguingly, iron and lipid metabolism are also pivotal for maintaining the physiological function of immune cells. Research has revealed that ferroptosis can potentiate the immunogenicity of tumor cells and engage in intricate interactions with immune cells. Certain ferroptosis inducers have the capacity to augment the efficacy of immunotherapy by modulating the tumor immune microenvironment. Ferroptosis holds immense potential in cancer immunotherapy and is anticipated to emerge as a novel therapeutic target in the future landscape of cancer treatment. In this review, we primarily delineate the ferroptosis signaling pathways and metabolic processes pertinent to immune cells, and further summarize the roles of ferroptosis in tumor-infiltrating immune cells. Ultimately, we anticipate further elucidation of the mechanisms of ferroptosis in immunotherapy and envision that strategies targeting ferroptosis and immunotherapy will be expeditiously applied in clinical oncology practice.

Integrating multi-omics data reveals the antitumor role and clinical benefits of gamma-delta T cells in triple-negative breast cancer

BACKGROUND

Gamma-delta (γδ) T cells are a critical component of the tumor microenvironment and have been recognized as a promising biomarker and target for cancer therapy. Increasing evidence suggests that γδT cells play distinct roles in different cancers. However, the impact of γδT cells in breast cancer remains controversial.

METHODS

In this study, we investigated the role of γδT cells in breast cancer using a comprehensive approach, including bulk and single-cell sequencing, radiomics based on magnetic resonance imaging (MRI), genomic data, and immunohistochemistry. Single-cell RNA profiling was used to infer the potential lineage evolution of γδT cells and their interactions with other immune cells. Bulk RNA sequencing was included to uncover the heterogeneity in signaling pathways, as well as radiotherapy and immunotherapy responses, among patients with varying levels of γδT cell abundance. Genomic analysis was used to recognize the critical gene mutations with the infiltration of γδT cells. Immunohistochemistry was performed to validate the prognostic value of γδT cells in breast cancer patients. Lastly, radiomics was used to establish a correlation between the abundance of γδT cells and the features of MRI images.

RESULTS

The γδT cell infiltration was closely associated with favorable prognosis in triple-negative breast cancer (TNBC) but not in other subtypes of breast cancer. γδT cells may exert antitumor effects through intrinsic lineage evolution or interact with antigen-presenting cells through ligand-receptor pairs. Patients with a high γδT cell abundance may benefit more from chemotherapy or radiotherapy alone than their combination. Additionally, patients with a high γδT cell abundance were more likely to benefit from immunotherapy. Finally, we established a radiomic model based on dynamic contrast-enhanced-MRI, which indicated the potential for estimating the γδT cell abundance for patients with TNBC.

CONCLUSION

Our study provides novel insight and a theoretical basis for individualized therapy of patients with TNBC based on γδT cells.

Single-cell sequencing exposes mast cell-derived CD52's anti-tumor action in breast cancer through the IL-6/JAK/STAT3 axis

The aggressive nature and rapid progression of triple-negative breast cancer (TNBC), coupled with a high likelihood of recurrence and mortality, underscore the critical need for effective treatments. While immunotherapy presents promising advantages for those with triple-negative breast cancer (TNBC), its efficacy is not universal. This disparity highlights the importance of investigating survival outcomes and prognostic factors for those TNBC patients who don't respond well to immunotherapy. Our study leverages both bulk and single-cell RNA sequencing data to conduct an in-depth analysis, revealing that genes associated with mast cells (PCMT1, VDAC1, YWHAB, BRD4, BTG1, and CD52) are pivotal in prognostication for TNBC patients. Laboratory experiments have further substantiated our findings, demonstrating that the overexpression of CD52 in mast cells impedes the proliferation, invasion, and metastasis of breast cancer cells. Further anti-CD52 treatment inhibiting breast tumor growth in vivo. Additionally, we have discovered that CD52 elicits its antitumor effects by meditating the IL-6/JAK/STAT3 signaling pathway. These insights not only enhance the prognostic significance of mast cells in TNBC but also pave the way for the development of novel targeted immunotherapy strategies.

Phenotypes and cytokines of NK cells in triple-negative breast cancer resistant to checkpoint blockade immunotherapy

Neoadjuvant checkpoint blockade immunotherapy (NATI) significantly prolonged outcomes for triple-negative breast cancer (TNBC). Residual tumor cells that survive NATI represent high-risk cell populations with metastatic potential and usually evade immunosurveillance by NK cells. Using an 82-protein panel, we here profiled single-cell membrane proteomics of CD56+ (NCAM1+) NK cells from tumor, peri-cancerous tissue, as well as peripheral blood from 28 TNBC patients post-NATI of residual cancer burden II/III. Unsupervised clustering resulted in several distinct clusters: 2 tumor-infiltrating NK (TINK) clusters with divergent functions of immune activation (TNFRSF7+) and suppression (SELL+); 2 immuno-suppressive peri-cancerous clusters; and 1 periphery-specific cluster. Considering the contradiction of the 2 TINK clusters, we further tested cytokine functions of SELL + and TNFRSF7 + TINKs by single-cell secreting proteomics using a 32-cytokine panel. Consistently, SELL + TINK clusters were characterized by immuno-suppressive secretion patterns (IL10+). A low proportion of SELL + TINK cluster and low proportion of IL10 + secreting SELL + TINK cluster (single-cell secreting proteomics) were both associated with better progression-free survival time. These findings were validated in an independent cohort of 15 patients during 16-month follow-up. Overall, we identified a distinct immuno-suppressive TINK cell group, featuring IL10 + secreting and SELL expression with a strong relation to poor survival prognosis in TNBC patients post-NATI.

Efficacy and Safety of Immunochemotherapy in Advanced Triple-negative Breast Cancer: A Meta-analysis of Randomised Clinical Trials

AIMS

Based on the existing controversial clinical research results, this study conducted a comprehensive meta-analysis of relevant literature to clarify the benefits of immunochemotherapy (ICT)-which combines immune checkpoint inhibitors and chemotherapy (CT)-for patients with advanced triple-negative breast cancer (aTNBC).

MATERILAS AND METHODS

A thorough literature search was conducted up to February 15, 2024. Subsequently, meta-analyses were performed to aggregate hazard ratios (HRs) for progression-free survival (PFS) and overall survival (OS), odds ratios (ORs) for objective response rate (ORR) and relative risks (RRs) for adverse events (AEs).

RESULTS

Six randomised clinical trials (RCTs) involving 3,105 patients met the inclusion criteria. In comparison with CT, ICT yielded significant enhancements in PFS (HR, 0.80; 95%CI: 0.73-0.87), OS (HR, 0.87; 95%CI: 0.80-0.96), and ORR (OR, 1.34; 95%CI: 1.15-1.55) in the intention-to-treat population. However, ICT also exhibited an increase in grade ≥3 AEs (RR, 1.11; 95%CI: 1.04-1.19) and severe AEs (RR, 1.40; 95%CI: 1.18-1.66). Subgroup analyses revealed that ICT significantly improved PFS (HR, 0.67; 95%CI: 0.58-0.77), OS (HR, 0.75; 95%CI: 0.64-0.87), and ORR (OR, 1.47; 95%CI: 1.16-1.84) within the PD-L1-positive subgroup, whereas no statistically significant differences were detected for PD-L1-negative population.

CONCLUSION

ICT demonstrates superior efficacy over conventional CT in the treatment of aTNBC, albeit accompanied by heightened toxicity. Notably, the assessment of PD-L1 status may serve as a valuable biomarker in discerning aTNBC patients who are particularly predisposed to derive benefit from ICT.

PROSPERO NUMBER

CRD42024513270.

Liquid biopsy for guiding breast cancer immunotherapy

Liquid biopsy is a laboratory test used to detect and analyze circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), and other tumor-derived components, in a blood sample. In the context of breast cancer (BC), liquid biopsies hold significant promise for guiding the use of immune checkpoint inhibitors and immune-based combinations, offering real-time insights into tumor dynamics, treatment response, and resistance mechanisms. This review explores the role of liquid biopsy in BC immunotherapy, focusing on its applications, benefits, issues, and current and future research directions.

Celastrol-loaded ginsenoside Rg3 liposomes enhance anti-programmed death ligand 1 immunotherapy by inducing immunogenic cell death in triple-negative breast cancer

BACKGROUND

Triple-negative breast cancer (TNBC), characterized by high heterogeneity and invasiveness. Currently, inducing immunogenic cell death (ICD) of tumor cells through approaches such as radiotherapy and chemotherapy is an effective strategy to enhance the response to anti-programmed death-ligand 1 antibody (aPD-L1) therapy in TNBC. However, radiotherapy and chemotherapy treatments often upregulate PD-L1 expression in tumor cells, thereby weakening the tumor cells' response to aPD-L1. Celastrol exhibits broad-spectrum and potent anti-tumor activity, efficiently inducing ICD without increasing PD-L1 levels in tumor cells.

PURPOSE

This study aims to elucidate the tumor-targeting effects of celastrol-loaded liposomes and its synergistic efficacy and mechanism of action in combination with aPD-L1 against TNBC.

METHODS

The Rg3 liposomes loaded with celastrol (Cel-Rg3-Lp) were prepared using the thin-film hydration method. BALB/c mice were utilized to establish an in situ breast cancer model. Mice were intravenously injected with Cel-Rg3-Lp at a dosage of celastrol 1 mg/kg once every two days for a total of 7 injections. Flow cytometry, western blot, and immunofluorescence techniques were employed to investigate the synergistic effects and mechanisms of Cel-Rg3-Lp combined with aPD-L1 in the treatment of TNBC.

RESULTS

The findings of this study demonstrate that after 7 administrations of Cel-Rg3-Lp (1 mg/kg celastrol, intravenously), significant anti-tumor effects are observed, including the recruitment of CD8+T cells and dendritic cells (DCs), while reducing the infiltration of immunosuppressive cells. The therapeutic efficacy was further enhanced when combined with aPD-L1. Additionally, Cel-Rg3-Lp markedly downregulated glucose-regulated protein 78 (GRP78) expression, thereby inducing ICD in tumor cells.

CONCLUSION

This study successfully constructed a multifunctional liposome and proposed a mechanism for inducing ICD through the GRP78-endoplasmic reticulum stress pathway. The liposome downregulates GRP78, triggering endoplasmic reticulum stress in tumor cells, inducing ICD, activating DCs, and enhancing antigen presentation to T cells. This improves the tumor immune microenvironment and provides a theoretical foundation for combining Cel-Rg3-Lp with aPD-L1 in the treatment of TNBC. This mechanism opens unique prospects for using celastrol in TNBC therapy and enhancing the effectiveness of immunotherapy.

Mapping molecular landscapes in triple-negative breast cancer: insights from spatial transcriptomics

The tumor microenvironment (TME) of triple-negative breast cancer (TNBC) is a highly heterogeneous and very aggressive form of the disease that has few suitable treatment options; however, spatial transcriptomics (ST) is a powerful tool for elucidation of the TME in TNBC. Because of its spatial context preservation, ST has a unique capability to map tumor-stroma interactions, immune infiltration, and therapy resistance mechanisms (which are key to understanding TNBC progression), compared with conventional transcriptomics. This review shows the use of ST in TNBC, its utilization in spatial biomarker identification, intratumoral heterogeneity definition, molecular subtyping refinement, and prediction of immunotherapy responses. Recent insight from ST-driven insights has explained the key spatial patterns on immune evasion, chemotherapy resistance, racial disparities of TNBC, and aspects for patient stratification and therapeutic decision. With the integration of ST with the subjects of proteomics and imaging mass cytometry, this approach has been enlarged and is now applied in precision medicine and biomarker discovery. Recently, advancements in AI-based spatial analysis for tumor classification, identification of biomarkers, and creation of therapy prediction models have occurred. However, continued developments in ST technologies, computational tools, and partnerships amongst multiple centers to facilitate the integration of ST into clinical routine practice are needed to unlock novel therapeutic targets.

New progress in imaging diagnosis and immunotherapy of breast cancer

Breast cancer (BC) is a predominant malignancy among women globally, with its etiology remaining largely elusive. Diagnosis primarily relies on invasive histopathological methods, which are often limited by sample representation and processing time. Consequently, non-invasive imaging techniques such as mammography, ultrasound, and Magnetic Resonance Imaging (MRI) are indispensable for BC screening, diagnosis, staging, and treatment monitoring. Recent advancements in imaging technologies and artificial intelligence-driven radiomics have enhanced precision medicine by enabling early detection, accurate molecular subtyping, and personalized therapeutic strategies. Despite reductions in mortality through traditional treatments, challenges like tumor heterogeneity and therapeutic resistance persist. Immunotherapies, particularly PD-1/PD-L1 inhibitors, have emerged as promising alternatives. This review explores recent developments in BC imaging diagnostics and immunotherapeutic approaches, aiming to inform clinical practices and optimize therapeutic outcomes.

Natural Products as Novel Therapeutic Agents for Triple-Negative Breast Cancer: Current Evidence, Mechanisms, Challenges, and Opportunities

Breast cancer (BC) tops the list of causes for female fatalities globally, with the elusive triple-negative breast cancer (TNBC) constituting 10-20% of all cases. Current clinical strategies for combating TNBC encompass a multifaceted approach, including surgical intervention, radiation therapy, chemotherapy, and advanced targeted drugs and immunotherapies. While these modalities have catalyzed significant advancements in TNBC management, lingering limitations continue to pose formidable challenges. There is an acute need for novel therapeutics in the realm of TNBC treatment. Natural products (NPs) have emerged as a rich reservoir for pharmaceutical innovation, owing to their extraordinary range of structures and physicochemical properties. Scholars have reported diverse evidence of NPs' efficacy against TNBC. This review aims to comprehensively explore the bioactive constituents, specifics and commonalities of chemical structure, and pharmacological mechanisms of NPs, specifically examining their multifaceted roles in impeding TNBC. NPs, which have recently garnered significant interest, are intriguing in terms of their capacity to combat TNBC through multifaceted mechanisms, including the suppression of tumor cell proliferation, the induction of apoptosis, and the inhibition of tumor metastasis. These natural agents primarily encompass a range of compounds, including terpenoids, glycosides, phenolic compounds, and alkaloids. An in-depth exploration has unveiled their involvement in key signaling pathways, including the transforming growth factor-beta (TGF-β), vascular endothelial growth factor A (VEGFA), phosphoinositide 3-kinase/protein kinase B (PI3K/AKT), Wingless/Int-1 (Wnt) /β-catenin, and mitogen-activated protein kinase (MAPK) pathways. Meanwhile, this review also looks at the challenges and opportunities that arise from harnessing natural compounds to influence TNBC, while outlining the prospective trajectory for future research in the field of NPs.

Gamabufotalin loaded micro-nanocomposites for multimodal therapy of metastatic TNBC by efficiently inducing ICD

Gamabufotalin (CS-6), a main active compound derived from Chinese medicine Chansu, exhibits a robust inhibitory effect on programmed death-ligand 1 (PD-L1) in triple-negative breast cancer (TNBC) cells. Despite its potential for tumor therapy, the medical application of CS-6 is constrained by its hydrophobic nature, lack of targeting capability, and weak immunogenic cell death (ICD) effect. To address these limitations and improve the therapeutic efficiency of this drug against metastatic TNBC, we designed a new kind of CS-6@CPB-S.lux that integrates carboxy-Prussian blue nanoparticles (CPB NPs), CS-6, and attenuated Salmonella typhimurium (S.lux) for TNBC therapy. In vitro and in vivo results have confirmed that CS-6@CPB NPs were efficiently delivered to neoplastic tissue by the tumor hypoxic chemotaxis property of S.lux, wherein the nanomedicine induced significant tumor cell necroptosis and apoptosis via photothermal therapy (PTT) of CPB NPs and chemotherapy of CS-6, which elicited ICD and inhibited PD-L1 expression, resulting in dendritic cells (DCs) maturation and effector T cells activation to comprehensively eliminate tumors. Additionally, the CS-6@CPB-S.lux + Laser treatment significantly transformed the immunosuppressive tumor microenvironment (TME), enhancing antitumor immunity through promoting the polarization of tumor-associated macrophages into antitumorigenic M1 and reducing Tregs recruitment. Consequently, this comprehensive therapy not only inhibited primary and abscopal tumor progression but also prevented TNBC metastasis, which significantly prolonged survival time in animal models. In summary, these findings indicated an alternative approach for metastatic TNBC therapy.

Extracellular matrix cancer-associated fibroblasts promote stromal fibrosis and immune exclusion in triple-negative breast cancer

The impact of high heterogeneity of cancer-associated fibroblasts (CAFs) on triple-negative breast cancer (TNBC) immunotherapy response has not been fully elucidated, restricting progress in precision immuno-oncology. We integrated single-cell transcriptomic data from 18 TNBC patients and analyzed fibroblast subpopulations. Extracellular matrix CAFs (ecmCAFs) were identified as a fibroblast subpopulation with distinct ECM-associated characteristics. The ecmCAFs were significantly enriched in TNBC patients with residual disease after neoadjuvant immunotherapy and contributed to a fibrotic tumor microenvironment and T-cell exclusion. Secreted phosphoprotein 1 (SPP1) positive macrophages (SPP1+ Mφs) were closely localized to ecmCAFs and produced more transforming growth factor beta (TGFB1), interleukin 1 beta (IL1B), and SPP1 under hypoxic conditions. SPP1+ Mφs were found to facilitate the differentiation of normal breast fibroblasts to ecmCAFs, thus promoting ECM remodeling and stromal fibrosis. Our work revealed the critical role of ecmCAFs in generating a desmoplastic architecture and driving immunosuppression in TNBC. © 2025 The Pathological Society of Great Britain and Ireland.

Engineering a Self-Delivery Nanoplatform for Chemo-Photodynamic-Immune Synergistic Therapies against Aggressive Melanoma

The effectiveness of immunotherapy in killing melanoma is hindered by a T-cell deficiency and the lack of tumor immunogenicity. Consequently, there is an urgent need for a platform that can further activate the immune system and boost the immune response of the host to tumors. Compared with monotherapy, combination therapy shows promise in improving treatment efficacy and response rates. This study introduces the pioneering use of a rationally designed active targeting nanoplatform to bind axitinib, paclitaxel, and verteporfin to human serum albumin (APV@HSA NPs). APV@HSA NPs have demonstrated the capability to induce dual-induced apoptosis in tumor cells through chemo- and photodynamic effects, while also enhancing immunogenic cell death and promoting dendritic cell maturation. Additionally, the platform promoted the production of CD8+ T cells and memory T cells and inhibited vascular endothelial growth factor via axitinib, facilitating the infiltration of immune effector cells and optimizing chemo-photodynamic immunotherapy. Hence, amplified chemo-photodynamic-immunological nanomedicines with excellent biocompatibility have been redesigned to inhibit the tumor microenvironment and combat the growth of primary tumor and lung metastasis. This approach initiates a series of immune responses, presenting a promising therapeutic strategy for melanoma.

A responsive cocktail nano-strategy breaking the immune excluded state enhances immunotherapy for triple negative breast cancer

The exclusion of immune cells from the tumor can limit the effectiveness of immunotherapy in triple negative breast cancer (TNBC). The cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway plays a crucial role in priming adaptive anti-tumor immunity through the production of type I interferons (IFNs), facilitating the maturation of dendritic cells (DCs) and the function of T cells. Although the increased expression of programmed death-ligand 1 (PD-L1) upon STING activation is favorable for amplifying the efficacy of immune checkpoint inhibitors (ICIs) and realizing combination therapy, the penetration barrier remains a major obstacle. Herein, we fabricated a smart-responsive nanosystem (B&V@ZB-MCL) by integrating the extracellular matrix (ECM)-degrading drug losartan with a STING agonist (Vadimezan, abbreviated to Vad) and a PD-L1 inhibitor (BMS-1). Losartan was first released in the acidic tumor microenvironment to overcome the physical barrier, enhancing the penetration of immunotherapeutic components. Under the triggering of 1O2 generated by a photosensitizer (Ce6), the reactive oxygen species (ROS)-sensitive degradation of the nanocore ensured the site-directed release of Vad and BMS-1. The released Vad and damaged tumor DNA activated immune responses through the cGAS-STING pathway, while the elevated expression level of PD-L1 promoted the anti-tumor effect of BMS-1. Significant degradation of collagen fibers, restoration of immune effector cells, and lower tumor volume were observed in this integrated triple drug sequential therapy, which provides a promising prospect for TNBC treatment.

Exosome Platform with Three-in-One Functionality of mRNA Therapy, Immune Checkpoint Blockade, and Mild Photothermal Therapy for the Treatment of Triple-Negative Breast Cancer

Immune checkpoint blockade (ICB) has shown promising potential for treating triple-negative breast cancer (TNBC), but its efficacy is limited, mainly due to the "cold," suppressive immune tumor microenvironment (TME). Therefore, improving the TME is crucial for enhancing therapeutic effects against TNBC. Here, we presented a multifunctional nanotherapeutic platform (ALEvs@LNPs) designed to combine cytokine-sensitized mild photothermal therapy, ICB, and interleukin-2 (IL2) mRNA therapy to reprogram the TME, thereby improving the efficacy of ICB therapy in TNBC. Tumor cell-derived exosome-camouflaged lipid nanoparticles with antilymphocyte activation gene-3 (LAG3) were developed to codeliver the photothermal agent IR806, IL2 mRNA, and LAG3 inhibitory antibody (anti-LAG3). Mild photothermal therapy facilitated the reprogramming of "cold" tumors into "hot," thereby enhancing the therapeutic effects of ICB. Meanwhile, ICB also promoted cytokine secretion, increasing the sensitivity of tumor cells to heat. Additionally, IL2 mRNA therapy induced T-cell proliferation and activation, further augmenting the efficacy of ICB. Together, these three therapies established a positive feedback loop that enhanced the therapeutic effects of ICB. This multifunctional nanotherapeutic platform effectively reprogrammed the "cold," suppressive immune TME, offering a promising strategy for TNBC treatment.

Comprehensive single-cell analysis of triple-negative breast cancer based on cDC1 immune-related genes: prognostic model construction and immunotherapy potential

BACKGROUND

Various components of the immunological milieu surrounding tumors have become a key focus in cancer immunotherapy research. There are currently no reliable biomarkers for triple-negative breast cancer (TNBC), leading to limited clinical benefits. However, some studies have indicated that patients with TNBC may achieve better outcomes after immunotherapy. Therefore, this study aimed to identify molecular features potentially associated with conventional type 1 dendritic cell (cDC1) immunity to provide new insights into TNBC prognostication and immunotherapy decision-making.

METHODS

Single-cell ribonucleic acid sequencing data from the Gene Expression Omnibus database were analyzed to determine which genes are differentially expressed genes (DEGs) in cDC1s. We then cross-referenced cDC1-related DEGs with gene sets linked to immunity from the ImmPort and InnateDB databases to screen for the genes linked to the immune response and cDC1s. We used univariate Cox and least absolute shrinkage and selection operator regression analyses to construct a risk assessment model based on four genes in patients with TNBC obtained from the Cancer Genome Atlas, which was validated in a testing group. This model was also used to assess immunotherapy responses among the IMvigor210 cohort. We subsequently utilized single sample Gene Set Enrichment Analysis, CIBERSORT, and ESTIMATE to analyze the immunological characteristics of the feature genes and their correlation with drug response.

RESULTS

We identified 93 DEGs related to the immune response and cDC1s, of which four (IDO1, HLA-DOB, CTSD, and IL3RA) were substantially linked to the overall survival rate of TNBC patients. The risk assessment model based on these genes stratified patients into high- and low-risk groups. Low-risk patients exhibited enriched ''hot tumor'' phenotypes, including higher infiltration of memory-activated CD4 + T cells, CD8 + T cells, gamma delta T cells, and M1 macrophages, as well as elevated immune checkpoint expression and tumor mutational burden, suggesting potential responsiveness to immunotherapy. Conversely, high-risk patients displayed "cold tumor" characteristics, with higher infiltration of M0 and M2 macrophages and lower immune scores, which may be poorer in response to immunotherapy. However, experimental validation and larger clinical studies are necessary to confirm these findings and explore the underlying mechanisms of the identified genes.

CONCLUSION

This study developed a robust risk assessment model using four genes that effectively forecast the outcome of patients with TNBC and have the potential to guide immunotherapy. This model provided new theoretical insights for knowing the TNBC immune microenvironment and developing personalized treatment strategies.

DNA methylation and immune evasion in triple-negative breast cancer: challenges and therapeutic opportunities

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer characterized by the lack of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2). Chemotherapy remains the primary treatment option, yet TNBC frequently develops resistance, leading to relapse and metastasis. Emerging evidence highlights the potential of combining DNA methylation inhibitors with immune checkpoint inhibitors (ICIs). DNA methylation contributes to immune escape by silencing immune-regulatory genes, thereby reducing the tumor's visibility to immune cells. Reversing this epigenetic modification can reinvigorate immune surveillance and enhance the efficacy of immunotherapies. This review discusses the role of DNA methylation in TNBC progression and immune evasion, focusing on recent advances in combination therapies involving DNA methylation inhibitors and ICIs. We discuss the underlying mechanisms that enable these therapeutic synergies, preclinical and clinical evidence supporting the approach, and the challenges posed by tumor heterogeneity, drug resistance, and toxicity. Finally, we explore the potential for personalized treatment strategies incorporating multi-omics data to optimize therapeutic outcomes. The integration of epigenetic therapies and immunotherapy offers a promising avenue for improving survival in TNBC patients.

Advances in Ultrasound-Targeted Microbubble Destruction (UTMD) for Breast Cancer Therapy

Breast cancer is one of the most common types of cancer in women worldwide and is a leading cause of cancer deaths among women. As a result, various treatments have been developed to combat this disease. Breast cancer treatment varies based on its stage and type of pathology. Among the therapeutic options, ultrasound has been employed to assist in the treatment of breast cancer, including radiation therapy, chemotherapy, targeted immunotherapy, hormonal therapy, and, more recently, radiofrequency ablation for early-stage and inoperable patients. One notable advancement is ultrasound-targeted microbubble destruction (UTMD), which is gradually becoming a highly effective and non-invasive anti-tumor modality. This technique can enhance chemical, genetic, immune, and anti-vascular therapies through its physical and biological effects. Specifically, UTMD improves drug transfer efficiency and destroys tumor neovascularization while reducing toxic side effects on the body during tumor treatment. Given these developments, the application of ultrasound-assisted therapy to breast cancer has gained significant attention from research scholars. In this review, we will discuss the development of various therapeutic modalities for breast cancer and, importantly, highlight the application of ultrasound microbubble-targeted disruption techniques in breast cancer treatment.

RBM15 Drives Breast Cancer Cell Progression and Immune Escape via m6A-Dependent Stabilization of KPNA2 mRNA

BACKGROUND

Breast cancer is the most frequently diagnosed cancer among women worldwide with high morbidity and mortality. Previous studies have indicated that RNA-binding motif protein-15 (RBM15), an N6-methyladenosine (m6A) writer, is implicated in the growth of breast cancer cells. Herein, we aimed to explore the function and detailed mechanism of RBM15 in breast cancer.

METHODS

In this research, UALCAN databases were applied to analyze the expression of RBM15 or Karyopherin-2 alpha (KPNA2) in BRCA. RBM15 and KPNA2 mRNA levels were determined using real-time quantitative polymerase chain reaction (RT-qPCR) assay. RBM15, KPNA2, and Programmed cell death ligand 1 (PD-L1) protein levels were measured using western blot. Cell proliferation, migration, and invasion were assessed using 5-ethynyl-2'-deoxyuridine (EdU) and Transwell assays. The biological role of RBM15 on breast cancer tumor growth was verified using the xenograft tumor model in vivo. Effects of breast cancer cells on the proliferation and apoptosis of CD8+ T cells were analyzed using flow cytometry. Interaction between RBM15 and KPNA2 was validated using methylated RNA immunoprecipitation (MeRIP) and dual-luciferase reporter assays.

RESULTS

RBM15 and KPNA2 were highly expressed in breast cancer tissues and cell lines. Furthermore, RBM15 silencing might suppress breast cancer cell proliferation, migration, invasion, and lymphocyte immunity in vitro, as well as block tumor growth in vivo. At the molecular level, RBM15 might improve the stability and expression of KPNA2 mRNA via m6A methylation.

CONCLUSION

RBM15 might contribute to the malignant progression and immune escape of breast cancer cells partly by modulating the stability of KPNA2 mRNA, providing a promising therapeutic target for breast cancer.

Characterization of Immune Landscape Based on Homologous Recombination Deficiency Associated Signatures and Identification of Knockdown of ERCC6L to Promote Radiosensitivity in Breast Cancer

BACKGROUND

Homologous recombination deficiency (HRD) exhibits significant associations with the occurrence, progression, and prognosis of breast cancer. However, the primary breast cancer HRD positivity rate is merely 24%. The identification of markers associated with HRD is crucial for the development of novel therapeutic approaches for breast cancer. The role of the oncogene ERCC6L in breast cancer remains unclear, and its interaction with radiotherapy has yet to be explored, necessitating further investigation for clarification.

METHODS

We employed WGCNA to identify genes associated with the HRD score, utilizing public HRD score and genetic data from TCGA breast cancer, with their clinical characteristics. Subsequently, we employed various machine learning methods to filter relevant genes. The final four genes were obtained through random forest and stepCox, and their performance was validated in TCGA, GSE96058, and METABRIC datasets. Next, we assessed the tumor immune microenvironment using methods such as ssGSEA, GSVA, CIBERSORT, ESTIMATE, and single-cell analysis. Finally, we validated the downregulation of ERCC6L, increasing DNA damage and enhancing radiation sensitivity, through immune fluorescence, flow cytometry, plate cloning, and western blot.

RESULTS

A prognostic model named HRAS was established through machine learning, consisting of four genes (ERCC6L, UBE2T, TPX2, and SLC7A5). The indicator exhibited excellent predictive performance on the prognosis and the efficacy of immunotherapy and radiotherapy of breast cancer patients in independent datasets. Breast cancer patients with high HRAS scores showed higher TMB and stemness, increased expression of immune checkpoints, reduced immune cell infiltration, and poorer prognosis in the context of immunotherapy and radiotherapy. Experimental validation demonstrated that knockdown of ERCC6L markedly elevated DNA damage, enhanced apoptosis, and induced cell cycle arrest in response to radiation therapy, thereby sensitizing cells to radiation.

CONCLUSION

The HRD-related signatures displayed strong predictive capabilities for the prognosis in multiple datasets and the efficacy of immunotherapy and radiotherapy of breast cancer patients. Moreover, the composite indicator reflected the immune microenvironment characteristics and could be novel markers for predicting the prognosis and clinical treatment outcomes in breast cancer patients. Our experiments first elucidated the role of ERCC6L in enhancing radiation-induced DNA damage, presenting a novel target for strategies aimed at sensitizing cancer cells to radiotherapy.

Amelioration of breast cancer therapies through normalization of tumor vessels and microenvironment: paradigm shift to improve drug perfusion and nanocarrier permeation

Breast cancer (BC) is the most commonly diagnosed cancer among women. Chemo-, immune- and photothermal therapies are employed to manage BC. However, the tumor microenvironment (TME) prevents free drugs and nanocarriers (NCs) from entering the tumor premises. Formulation scientists rely on enhanced permeation and retention (EPR) to extravasate NCs in the TME. However, recent research has demonstrated the inconsistent nature of EPR among different patients and tumor types. In addition, angiogenesis, high intra-tumor fluid pressure, desmoplasia, and high cell and extracellular matrix density resist the accumulation of NCs in the TME. In this review, we discuss TME normalization as an approach to improve the penetration of drugs and NCSs in the tumor premises. Strategies such as normalization of tumor vessels, reversal of hypoxia, alleviation of high intra-tumor pressure, and infiltration of lymphocytes for the reversal of therapy failure have been discussed in this manuscript. Strategies to promote the infiltration of anticancer immune cells in the TME after vascular normalization have been discussed. Studies strategizing time points to administer TME-normalizing agents are highlighted. Mechanistic pathways controlling the angiogenesis and normalization processes are discussed along with the studies. This review will provide greater tumor-targeting insights to the formulation scientists.

Combined use of immunoreactivities of Efp and ZCCHC3 for predicting prognosis of patients with triple-negative breast cancer

We previously reported that strong immunoreactivity (IR) of estrogen-responsive finger protein (Efp), also known as tripartite motif-containing 25 (TRIM25), predicts poor prognosis in patients with estrogen receptor-positive and -negative invasive breast cancers. In the present study, we investigated the clinicopathological role of Efp and ZCCHC3, the latter of which is an Efp interactor, in a triple-negative breast cancer (TNBC) cohort which was composed of 118 Japanese female breast cancer patients underwent surgical treatment. Efp and ZCCHC3 IRs were analyzed using specific antibodies for these proteins. We demonstrated that positive Efp IR was significantly associated with shorter distant disease-free survival (p = 0.0108) and that positive ZCCHC3 IR was also significantly associated with shorter distant disease-free survival (p = 0.0153). Notably, ZCCHC3 IR was positively associated with Efp IR (p = 0.003). When IRs of the two proteins were combined, double positivity was associated with shorter distant disease-free survival (p = 0.0007) and was an independent factor for poor prognosis. These results suggest that IR positivity of Efp and ZCCHC3 has clinical significance as a poor prognostic factor in patients with TNBC. Thus, we propose that the combined use of both IRs can be used as a prognostic marker for TNBC.

Manufacturing and Financial Evaluation of Peptide-Based Neoantigen Cancer Vaccines for Triple-Negative Breast Cancer in the United Kingdom: Opportunities and Challenges

This review evaluates the financial burden of current treatments for triple-negative breast cancer (TNBC) and projects potential financial scenarios to assess the feasibility of introducing a peptide-based neoantigen cancer vaccine (NCV) targeting the disease, using the UK as a healthcare system model. TNBC, the most aggressive breast cancer subtype, is associated with poor prognosis, worsened by the lack of personalised treatment options. Neoantigen cancer vaccine therapies present a personalised alternative with the potential to enhance T-cell responses independently of genetic factors, unlike approved immunotherapies for TNBC. Through a systematic literature review, the underlying science and manufacturing processes of NCVs are explored, the direct medical costs of existing TNBC treatments are enumerated, and two contrasting pricing scenarios for NCV clinical adoption are evaluated. The findings indicate that limited immunogenicity is the main scientific barrier to NCV clinical advancement, alongside production inefficiencies. Financial analysis shows that the UK spends approximately GBP 230 million annually on TNBC treatments, ranging from GBP 2200 to GBP 54,000 per patient. A best-case pricing model involving government-sponsored NCV therapy appears financially viable, while a worst-case, privately funded model exceeds the National Institute for Health and Care Excellence (NICE) cost thresholds. This study concludes that while NCVs show potential clinical benefits for TNBC, uncertainties about their standalone efficacy make their widespread adoption in the UK unlikely without further clinical research.

Mechanistic insights into pachymic acid's action on triple-negative breast Cancer through TOP2A targeting

Triple-negative breast cancer (TNBC) is characterized by the absence of estrogen and progesterone receptors, and lack of human epidermal growth factor receptor 2 (HER2) expression. Traditional Chinese medicine (TCM) has demonstrated promising efficacy in treating TNBC. This study explored the mechanisms of pachymic acid (PA) on TNBC by merging network pharmacology with experimental validation. We acquired Microarray data of TNBC from the Gene Expression Omnibus (GEO). The related targets of PA were predicted and screened using the following 6 databases: Swiss Target Prediction, HERB (Herbal Medicine Database), ETCM (Encyclopedia of Traditional Chinese Medicine), BATMAN (Bioinformatics Analysis Tool for Molecular Mechanism of Traditional Chinese Medicine), HIT (Herb Ingredients' Targets Database), and PharmMapper. The STRING interaction network analysis tool was used to create Protein-Protein Interaction (PPI) networks. Enrichment analysis included Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). We conducted a pan-cancer analysis, tumor immune microenvironment analysis, and molecular docking. We performed cell experimental, included cytotoxicity assay, apoptosis analysis, proliferation assay, and migration and invasion assays. PA has potential for treating TNBC with the target of TOP2A, and platinum drug resistance possibly serving as the KEGG pathway through which PA exerts its therapeutic effects. PA is involved in processes such as nuclear division, chromosome segregation, mitotic nuclear division, condensed chromosome formation, and protein C-terminus binding. PA probably exert its therapeutic effects through the tumor immune microenvironment, involving elements such as Dendritic cells activated, Eosinophils, Macrophages M0, Macrophages M1, and T cells CD4 memory activated. The therapeutic effects of PA may vary across different subtypes of TNBC such as TNBC-BL1, TNBC-Metaplastic, and TNBC-BL2. This study provides compelling evidence that PA holds significant promise as a therapeutic agent for TNBC, primarily through its action on TOP2A and its influence on the TNBC.

Deep Learning and Radiomics in Triple-Negative Breast Cancer: Predicting Long-Term Prognosis and Clinical Outcomes

Triple-negative breast cancer (TNBC) is a unique breast cancer subtype characterized by the lack of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) expression in tumor cells. TNBC represents about 15% to 20% of all breast cancers and is aggressive and highly malignant. Currently, TNBC diagnosis primarily depends on pathological examination, while treatment efficacy is assessed through imaging, biomarker detection, pathological evaluation, and clinical symptom improvement. Among these, biomarker detection and pathological assessments are invasive, time-intensive procedures that may be difficult for patients with severe comorbidities and high complication risks. Thus, there is an urgent need for new, supportive tools in TNBC diagnosis and treatment. Deep learning and radiomics techniques represent advanced machine learning methodologies and are also emerging outcomes in the medical-engineering field in recent years. They are extensions of conventional imaging diagnostic methods and have demonstrated tremendous potential in image segmentation, reconstruction, recognition, and classification. These techniques hold certain application prospects for the diagnosis of TNBC, assessment of treatment response, and long-term prognosis prediction. This article reviews recent progress in the application of deep learning, ultrasound, MRI, and radiomics for TNBC diagnosis and treatment, based on research from both domestic and international scholars.

The mechanism underlying metastasis in triple-negative breast cancer: focusing on the interplay between ferroptosis, epithelial-mesenchymal transition, and non-coding RNAs

Triple-negative breast cancer (TNBC) is a type of breast cancer with lack the expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2). It is the most aggressive breast cancer and the most difficult to treat due to its poor response to treatments and extremely invasive characteristics. The typical treatment for TNBC frequently results in relapse because of the lack of particular treatment choices. It is urgent to focus on identifying a workable and effective target for the treatment of TNBC. Cancer metastasis is significantly influenced by epithelial-mesenchymal transition (EMT). Ferroptosis is an iron-dependent cell death form, and changes its key factor to affect the proliferation and metastasis of TNBC. Several reports have established associations between EMT and ferroptosis in TNBC metastasis. Furthermore, non-coding RNA (ncRNA), which has been previously described, can also control cancer cell death and metastasis. Thus, in this review, we summarize the correlation and pathways among the ferroptosis, EMT, and ncRNAs in TNBC metastasis. Also, aim to find out a novel strategy for TNBC treatment through the ncRNA-ferroptosis-EMT axis.

Advances in Monoclonal Antibody Therapies for Triple-Negative Breast Cancer: Immunotherapeutic and Targeted Strategies

Triple-negative breast cancer (TNBC) presents considerable obstacles because of its highly aggressive characteristics and limited availability of specific therapeutic interventions. The utilization of monoclonal antibody (mAb)-based immunotherapy is a viable approach to tackle these difficulties. This review aims to examine the present state of mAb-based immunotherapy in TNBC, focusing on the underlying mechanisms of action, clinical applications, and existing challenges. The effectiveness of mAbs in reducing tumor development, regulating immune responses, and changing the tumor microenvironment has been demonstrated in many clinical investigations. The challenges encompass several aspects such as the discovery of biomarkers, understanding resistance mechanisms, managing toxicity, considering costs, and ensuring accessibility. The future is poised to bring forth significant advancements in the field of biomedicine, particularly in the areas of new mAbs, personalized medicine, and precision immunotherapy. In conclusion, mAb-based immunotherapy has promise in revolutionizing the treatment of TNBC, hence providing a possible avenue for enhanced patient outcomes and quality of life.

SKP2 inhibition activates tumor cell-intrinsic immunity by inducing DNA replication stress and genomic instability

BACKGROUND

S-phase kinase-associated protein 2 (SKP2) is a typical oncogene aberrantly overexpressing in a variety of cancer types, but it remains elusive whether SKP2 regulates the antitumor immunity of triple-negative breast cancer.

METHODS

The efficacy of anti-PD-1 was evaluated in the orthotopic xenografts of immunocompetent mice models. The infiltration of cytotoxic T cells in tumor microenvironment(TME) were assessed by immunofluorescence staining. The levels of pro-inflammatory chemokines were analyzed by ELISA. The protein interaction was analyzed by co-immunoprecipitation and GST pull-down. The genomic instability was analyzed by fluorescent microscopy.

RESULTS

SKP2 inhibition significantly improved the antitumor efficacy of immune checkpoint blockade (ICB). Furthermore, SKP2 inhibition activated the cGAS/STING signal pathway and induced the secretion of pro-inflammatory chemokines, thereby promoting cytotoxic T cell infiltration. Additionally, we identified CDC6, a DNA replication licensing factor as a novel substrate of SKP2 in addition to CDT1. SKP2 induced protein degradation of CDC6 and CDT1 through the ubiquitin-proteasome pathway. Conversely, SKP2 inhibition elevated CDC6 and CDT1 protein levels, which caused DNA aberrant replication, DNA damage and genomic instability, thereby resulting in the accumulation of cytosolic DNA, activating cGAS/STING signaling pathway and improving antitumor immunity.

CONCLUSION

SKP2 may be used as an effective therapeutic target to enable ICB antitumor immunotherapy.

SOCIAL MEDIA

Peng et al. found that SKP2 inhibition improved the antitumor immunotherapy by activating tumor cell-intrinsic immunity, thereby providing evidences that SKP2 may be used as an effective therapeutic target to enable ICB antitumor immunotherapy.

RAC2 as a Tumor-Suppressive Biomarker Associated with T Cell Infiltration in Breast Cancer

Background: RAC2 is critical in regulating the homeostasis of hematopoietic stem cells. Nonetheless, its role in breast cancer (BC) remains unclear, necessitating further investigation. Methods: The expression of RAC2 in BC and healthy tissues was acquired from The Cancer Genome Atlas. Its validity was further assessed using datasets from the gene expression omnibus database. The Tumor Immune Single-cell Hub database was used to collect and analyze the single-cell RNA sequencing datasets of BC. The diagnostic relevance of RAC2 was evaluated using receiver operating characteristic curves. Further assessment was carried out via enrichment analyses; Gene Set Analysis, immune scoring, single-cell sequencing, and immunohistochemical analysis were conducted to confirm the relationship between RAC2 expression and immune infiltration. Results: RAC2 expression was notably heightened in BC (p < 0.001). It was observed that a better prognosis was linked to heightened expression of RAC2 (p < 0.01), with the diagnostic efficacy of the marker noted to be good (area under the curve = 0.858). We found a lower percentage of protumor immune cells and a greater proportion of antitumor immune cells in the high RAC2. Our analysis revealed alterations in gene expression and an enriched network of immune pathways influenced by RAC2. Notably, cytotoxic genes, chemokines, chemokine receptors, immunostimulators, and immunosuppressive molecules positively correlated with RAC2 expression. RAC2 expression reliably predicted how patients would respond to two different therapeutic approaches in BC. Conclusions: The RAC2 was found to be a key biomarker in BC in the current study, demonstrating considerable potential as a prognostic and diagnostic marker. These results highlight the RAC2 potential to improve precision medicine strategies and treatment outcomes for patients with BC.

A Circadian Rhythm-related Signature to Predict Prognosis, Immune Infiltration, and Drug Response in Breast Cancer

PURPOSE

Circadian rhythm-related genes (CRRGs) play essential roles in cancer occurrence and development. However, the prognostic significance of CRRGs in breast cancer (BC) has not been fully elucidated. Our study aimed to develop a prognostic gene signature based on CRRGs that can accurately and stably predict the prognosis of BC.

METHODS

The transcriptome data and clinical information for BC patients were obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. A consensus unsupervised clustering analysis was carried out to investigate the roles of CRRGs in BC. A CRRGs-related prognostic risk model was established by using logistic least absolute shrinkage and selection operator (LASSO) Cox regression and univariate Cox regression analyses. Kaplan-Meier (KM) curves analysis, time-dependent receptor operation characteristics (ROC) curves analysis, and nomogram were plotted to evaluate the predictive efficacy of the model. The relevance of risk score to the immune cell infiltration, tumor burden mutation (TMB), and therapeutic response was assessed.

RESULTS

A risk model comprising six CRRGs (SLC44A4, SLC16A6, TPRG1, FABP7, GLYATL2, and FDCSP) was constructed and validated, demonstrating an effective predictor for the prognosis of BC. The low-risk group displayed a higher expression of immune checkpoint genes and a lower burden of tumor mutation. Additionally, drug sensitivity analysis demonstrated that the prognostic signature may serve as a potential chemosensitivity predictor.

CONCLUSION

We established a CRRGs-related risk signature, which is of great value in predicting the prognosis of patients with BC and guiding the treatment for BC.

Tumor microenvironment and immunotherapy for triple-negative breast cancer

Triple-negative breast cancer (TNBC) is a subtype of breast cancer known for its high aggressiveness and poor prognosis. Conventional treatment of TNBC is challenging due to its heterogeneity and lack of clear targets. Recent advancements in immunotherapy have shown promise in treating TNBC, with immune checkpoint therapy playing a significant role in comprehensive treatment plans. The tumor microenvironment (TME), comprising immune cells, stromal cells, and various cytokines, plays a crucial role in TNBC progression and response to immunotherapy. The high presence of tumor-infiltrating lymphocytes and immune checkpoint proteins in TNBC indicates the potential of immunotherapeutic strategies. However, the complexity of the TME, while offering therapeutic targets, requires further exploration of its multiple roles in immunotherapy. In this review, we discuss the interaction mechanism between TME and TNBC immunotherapy based on the characteristics and composition of TME, and elaborate on and analyze the effect of TME on immunotherapy, the potential of TME as an immune target, and the ability of TME as a biomarker. Understanding these dynamics will offer new insights for enhancing therapeutic approaches and investigating stratification and prognostic markers for TNBC patients.